1. Field of the Invention
This invention relates generally to electrical connectors in computer systems and specifically to a connector coupled to a sensor circuit for indicating when the connector is properly mated.
2. Description of the Related Art
In connector applications for computer systems, it is important to detect when the two halves of a connector have been substantially fully mated so that signals may be transmitted between various components in the system. In computer systems currently being manufactured, modular components are used to simplify assembly. The modules include connectors to interface with the computer system. As the modules increase in complexity and functionality, larger connectors with higher pin count are required. A common problem with the larger connectors is that they are more difficult to connect properly. One common problem is having pins near one or more sides of the connector that are not properly seated in a corresponding socket. The problems that may occur when a connector is not properly seated range from lost signals to damage to hardware components. It is therefore desirable to provide a sensor system for hardware connectors that indicates whether the connectors are properly mated.
Several mechanical devices for indicating whether a connector is properly seated currently exist in the prior art. For example, U.S. Pat. No. 4,906,204 pertains to an electrical connector with a connector position assurance device that slides into a gauge slot of the female connector body only when the connector bodies are properly engaged. U.S. Pat. No. 4,596,431 discloses a coupling indicator for an electrical connector which includes an expandable ring that expands during connector mating to extend outwardly of the external surface of a connector element. A user may touch the ring to determine whether the connector is mated. U.S. Pat. No. 5,605,471 teaches an electrical connector assembly having a connector position assurance device which includes a fin with a flexible locking arm to secure the device to a corresponding electrical connector to secure complete mating of the connector. None of these devices provide electronic sensing that may be integrated with a computer system so that the computer system can prevent certain operations from being performed when it senses that a required device is not properly connected.
U.S. Pat. No. 5,590,363 issued to Lunsford et al. teaches a detection circuit connected to the local bus in a computer system that receives a signal indicating the presence of a co-processor in a socket and outputs a first voltage when the co-processor unit is installed, and a second voltage when the co-processor unit is not installed. The Lunsford et al. device is designed specifically for co-processors and does not disclose a circuit that can be adapted to detect whether the mating portions of a variety of different connectors are properly seated.
U.S. Pat. No. 5,568,610 issued to Brown teaches a detection system for detecting the insertion or removal of expansion cards that have a standard edge connector using one or more capacitive plates coupled to corresponding variable frequency oscillators. The capacitive plates are mounted on an internal layer of the expansion card and are aligned with pins of the edge connector to establish capacitive loading with respect to the pins. The Brown device is designed to sense changes in the frequency of the oscillators and therefore is not capable of detecting whether the mating portions of a connector are properly seated.
In one embodiment, the present invention provides a sensing apparatus for detecting a disconnection in a connector for interfacing a component module in a computer system. A first portion of the connector is coupled to the computer system and a second portion of the connector is coupled to a component module in the computer system. The connector portions include electrically conductive portions that mate to enable communication between the component module and the computer system. The component module is addressable by the processing unit through a data bus.
To determine whether the connector portions are properly mated, one or more sense electrical signals are applied to one or more electrically conductive portions on the first portion of the connector. Each electrically conductive portion receives a unique signal, referred to herein as xe2x80x9csense signals.xe2x80x9d A set of corresponding electrically conductive portions on the second portion of the connector are connected to ground. With the connector portions mated, the sense signal(s) applied to the first portion of the connector are overridden by xe2x80x9cgroundxe2x80x9d on the second portion of the connector. Note that there must be one or more electrically conductive portions on the first portion of the connector electrically connected to system ground, and the electrically conductive portions must be mated to electrically conductive portions on the second portion of the connector which in turn are electrically connected to the component ground. A logic circuit provides an output signal indicative of whether the sense signal(s) are pulled to ground on the corresponding set of electrically conductive portions on the second portion of the connector. If the sense signal(s) are pulled to ground, then the logic circuit allows power to be supplied to the component module. When any one of the sense signals are not pulled to ground on any one or more of the corresponding electrically conductive portions on the second portion of the connector, the logic circuit prevents power from being applied to the component module. If the connector becomes partially unmated while power is applied to the module, the logic circuit will detect this and remove power to the module to attempt to prevent damage to the module. The output of the logic circuit may also be used to provide an indication to the user that there is a disconnection in the particular connector.
Several different logic circuits may be used in the present invention including an OR gate, a NOR gate, or a plurality of cascaded logic gates. The present invention may also be used with a variety of connectors including pin/socket type connectors, and tab/slot type connectors.
The foregoing has outlined rather broadly the objects, features, and technical advantages of the present invention so that the detailed description of the invention that follows may be better understood.